sticky valve lifters

I hear a "clicking" when engine runs. ive searched and from previous knowledge know that the valve lifters are sticking. It just started making the noise after i changed my oil. I changed the oil and used 10w-30. Ive also added some marvel mystery oil. Anyone have any input on this "mystery" oil? A couple of my friends have used it before and the sticking stoped for them. I added the "mystery oil" a couple of days ago. the sticking comes and goes. If i change my oil and use 20w-50 on an engine with 194,500 miles on it, will it decrease the sticking of the valve lifters and maybe stop it completely? Or is an adjustment nessesary? thanks for all your help.

Unfortunately not adjustable or replaceable unless you change the cam at the same time. 20w50 wont help the lifters, try running seafoam thru your crankcase for 750 miles.

So a heavier weight oil will do nothing then. I guess the mystery oil helps a little bit but ill give the sea foam a try for 750 miles and if it doesnt work out then ill have to replace the lifters and cam. thanks for the input.

With that many miles, chances are, many things in the motor are pretty loose. If the sound you are hearing is the lifters, I wouldn't worry about it too much.
Lifter noise, is often worse when the motor heats up and the oil thins some.
I've had pretty good luck with molybdenum based engine additives. Liquid moly seems to quiet things down some.
I usually run 10-40 in all old motors. A synthetic oil, also helps quiet things down. I've run 10-50 synthetic and it worked well for me. The synthetics are good because they don't get really thick in cold weather, so the heavier oil, doesn't slow down the starter much.
The down side to synthetics, is they clean the gunk out of the motor and the gunk is sometimes the only thing holding the oil in (the seals and gaskets start leaking).
There is no adjustment for the valves or lifters. How is your oil pressure?
Are they really clattering or is it just a tick. Or does it sound like a knock. I've seen some pretty worn connecting rod bearings on motors with a whole lot less mieage than yours.

oil pressure is a steady 40 when at idle and as i accelerate it reaches about 60-70 and stays at higher rpms.

Are they really clattering or is it just a tick? Have you listen to different areas on the motor, with a piece of tubing held to your ear? I´ve heard worn distributor gears make a fairly serious clacking.

Oh, and the noise is just a tick, a continuous tick. no knocking or clattering. A very seperated and clean tick, if that makes sense. lol.

its comin from the manifold side.

It's really hard to tell with the unaided ear. Try localizing it with a piece of tubing held to various spots and your ear, see where it's the loudest. You can usually hear, loud push rods and such, out of the oil filler hole when you open the cap. If it's coming from the manifold side, it could even be the dreaded exhaust manifold crack, the sound it makes is often very near a valve clack.

alright, ill do that tomorrow. ill take a hose to every part of the motor and try to pin point the noise and make sure it is infact just a tick and not a nock or clatter. hopefully its just the manifold as u stated. ill let u know and as well as post in this tomorrow. thanks for all your help, greatly appreciated.

The thing is, the 4.0 with that many miles is bound to make some "normal" engine noise. There are alot of things that make similar ticking sounds from piston slap to rocker arm noise to injector noise, valves, leaking exhaust, worn distributors ore even more serious low end knock. You need to pinpoint the noise location with a stethoscope, neoprene hose or wooden dowel.

The lifters on the 4.0 are located on the same side as the distributor by the way, pull the valve cover and check things out, won't hurt to look under there and check the condition of the valvetrain.

I think we ought to do a segment on the sounds an XJ makes, so far today it has been a pop, a tick and heavy breathing. Kind of sounds like me getting out of bed in the mroning.

will do, ill pull of th cover as well to check things out. ive changed the oil every 3,000 miles ever since it was new so... but anyways, yea the 4.0L does make many noises and every noise it has made in the past has gone away. I just like to figure out what the noise is and diagnose it as soon as possible.

I think we ought to do a segment on the sounds an XJ makes, so far today it has been a pop, a tick and heavy breathing. Kind of sounds like me getting out of bed in the morning.

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:laugh:

Yeah, I sometimes think the XJ is trying to tell me something. Mine usually starts with a some reluctance and grumbling which is how I start my day. The only effective solution to quieting my motor down was installing a louder exhaust. Funny, people have been bringing this up, my dad was outside last week and I pulled up in the Jeep, he keeps nagging me that theres something wrong with the Jeep. BTW I hadn't realized I posted the same info by the time I finished.

bajacalal said:

:laugh:

Yeah, I sometimes think the XJ is trying to tell me something. Mine usually starts with a some reluctance and grumbling which is how I start my day. The only effective solution to quieting my motor down was installing a louder exhaust. Funny, people have been bringing this up, my dad was outside last week and I pulled up in the Jeep, he keeps nagging me that theres something wrong with the Jeep. BTW I hadn't realized I posted the same info by the time I finished.

Click to expand...

Sure enough, a sport exhaust and a couple of additional speakers, will quiet them down everytime.
In the last two months, I replaced a wheel hub that was roaring, then noticed a rod bearing knock that I fixed, then a ball joint pop, right, then a ball joint pop left, then a drag link end pop (both ends), my distributor stopped rattling all on it´s own, then my crossover pipe was banging the cross brace. Now I´m down to one pop, the only ball joint I didn't change the last two tries and then the motor starts pissing all over the street from the rear main seal. I did pass the emissions test with flying colors :us:, but the guy at the inspection station flunked my tires, because the speedo was off. Fun with XJ's.

I'm not sure what's in MMO offhand, but it usually works (as long as your lifters haven't collapsed yet - they shouldn't have.) It might take an oil change or two.

You won't have to pull the cam if you need to change lifters, but you DO need to pull the head - and that's enough of a pain as it is.

I'd not suspect any other problems down below, as long as your oil pressure is good.

Did you still want me to show you how to rig the RENIX fan bypass switch? I'm still at DA - I'm in the day programme now. You can catch me around noon TUE-FRI.

5-90

My understanding is that lifters and cam are to be changed at the same time since they have been running together for so many miles and have wear patterns that match. One other thing on the 4.0 that may tick is the flywheel bolts.